Universal Serial Bus (USB) is a serial bus standard commonly applied for computer, communication, and consumer electronics. Due to the developments of products in different aspects, demands for higher transmission speeds are urging. During high frequency signal transmission, severe crosstalk between terminals may occur in the case of the common USB 2.0 interfaces. In addition, the conventional USB 2.0 interfaces may suffer from radiofrequency interference (RFI) as well as electromagnetic interference (EMI) easily.
Regarding to the USB 3.0 interfaces, the crosstalk and interference problems may become serious due to the higher transmission speed which can be more than 5 Gbs of the USB 3.0 interfaces. To reduce the crosstalk, conventionally, a metallic grounding plate is positioned between upper and lower terminals. To reduce the radiofrequency interference and the electromagnetic interference, a metallic shell is applied to enclose the terminals. Nevertheless, the metallic shell commonly has a rear cover, which may increase the difficulty for soldering tail portions of the terminals on the circuit board during a packaging procedure.
Moreover, common soldering legs includes through-hole legs and flat legs (legs manufactured by surface mount technology). To standardize the soldering procedures of the circuit boards, in some cases the circuit board may include additional insertion holes or grooves. Therefore, upon the soldering procedure, solder empty or non-wetting problems may occur. Due that the structures of the components become complex and due to the aforementioned structure of the metallic shell, a person cannot check if holes or grooves of the circuit board are properly mated with the terminals (i.e., whether or not the pin assignments between the circuit board and the terminals are in right positions), and the connector may be difficult to be repaired. As a result, once the connector is damaged, the whole receptacle has to be detached from the assembled circuit board and repaired separately. Therefore, the overall cost for repairing the connector assembly may be very expensive.